Recently, in a confectionery shop at the basement of a department store, a convenience store, a supermarket, or the like, there have been more opportunities to sell various kinds of food on display in a showcase by lighting up with a strong fluorescent lamp for prolonged periods of time to put them look better, from reasons to emphasize the freshness and safety of food and to help consumers have a sense of safety. Dessert and cakes such as pudding, coffee jelly, fruit juice jelly, mousse, etc., on which cream of an oil-in-water type emulsion is topped are also included in these kinds of food (herein, sometimes, referred to as light-exposing food), and a whippable oil-in-water type emulsion is used in cakes. In this case, an ingredient in food on display is changed due to energy provided by irradiation of light, which causes off-taste and off-flavor. The phenomenon of food deterioration by causing off-taste and off-flavor in this way is generally called photodegradation. This phenomenon reduces a commercial value of food by deteriorating taste, and thus preventive measures against photodegradation present a great challenge in quality preservation. In particular, cream of an oil-in-water type emulsion to be used for topping of dessert and a whippable oil-in-water type emulsion to be used for cake are highly likely affected by photo-irradiation due to be in position easy to be exposed to photo-irradiation.
Further, the above-described pudding is one kind of dessert and attracts kids and adults with its taste, mouthfeel and the like. To meet their preferences and demands, a variety of formulations of ingredients and production processes have been proposed. Pudding can be divided into two main types, one is a custard type hardened by thermocoagulation of eggs, and the other is a gel type hardened by a gelling agent. The custard type is made of eggs, milk products and sugars as main ingredients. Examples of the eggs include whole egg, egg yolk, egg white and the like, and examples of the milk products include cow milk, concentrated milk, whole milk powder, skim milk powder, fresh cream, compound cream, vegetable cream, natural cheese, processed cheese, cheese foods and the like. While cow milk is used as direct drinks, it is also used as a blending material into pudding, bavarois, jelly, etc. The gel type is made of milk products, a gelling agent and sugars as main ingredients. Examples of the gelling agent include gelatin, carrageenan, etc. Recently, in a confectionery shop at the basement of a department store, a convenience store, a supermarket, etc., various kinds of food are sold on display in a showcase by lighting up with a strong fluorescent lamp for prolonged periods of time. Pudding is also one of those kinds of food. In this case, an ingredient in food on display is changed due to energy provided by irradiation of light, which causes off-taste and off-flavor. The phenomenon of food deterioration by causing off-taste and off-flavor in this way is generally called photodegradation. This phenomenon reduces a commercial value of food by deteriorating taste, and thus preventive measures against photodegradation present a great challenge in quality preservation.
To prevent the photodegradation, various agents for preventing taste deterioration have been added to food as a substance having a preventive effect against photodegradation. For example, in JP 2003-33164 A, myricetin and quercetin are used together in a specific blend ratio; in JP 11-341971 A, propolis is used; and in JP 10-183164 A, at least one ingredient selected from chlorogenic acid, caffeic acid, and ferulic acid is used. However, the amount of the agent to be used has restricted because its taste comes out if it is added too much, and especially in an oil-in-water type emulsion, a sufficient effect has hardly been able to be achieved only by the agent.